Resistance to dirt is important in applications where the finished product is exposed to contamination. Sources of contamination include, for example, soil, air pollution, toxic gases, hydrolysis or fluids, and chemicals. Applications such as textile architecture, roofing membranes, geo-membranes, industrial tank liners, industrial containers, industrial packaging, automotive dashboards—are some examples of end-products exposed to contamination.
Resistance to dirt (or contamination) is measured quantitatively as dirt pick-up resistance (or DPUR). Conventionally, materials such as polyolefins, achieve DPUR by (i) applying a special coating thereto (coating based on acrylic, polyurethane, fluoro-silane, polyvinyl dichloride, UV curing inks), and/or (ii) surface modification techniques (gas phase fluorination, electron beam grafting), and/or (iii) the use of surface modifiers (polydimethylsiloxanes, nano-silica).
The art recognizes the need for materials that have DPUR without the need for a coating or a secondary production process.